Researchers at the Massachusetts Institute of Technology have developed an inexpensive handheld device called the eyeSelfie to allow patients to image their own retinas.

The eyeSelfie, which works like a point-and-shoot camera, helps users align their gaze properly, so they can take clear retinal selfies, one eye at a time.

As the patient looks into the device, a red light that shines through tiny holes to make it look as if there are four red lights in a diamond formation in his device. Patients initially see the lights as dim dots but, as they move their eyes around, they quickly notice that the dots become brighter when they look in a specific direction.

When these dots become particularly bright, a second diamond of dim red lights becomes apparent inside the first four. The person then moves their eyes again until they can see all eight bright lights forming a diamond within a diamond. This is the patient’s cue to snap the button. Experts would then evaluate the retinal selfie.

Researchers are already developing software capable of analyzing the retina in more detail and plotting that information over time.